for my $file (@list_of_files) {

    open my $read, '<', $file or die $!;
    my $count = 0;
    my $new_name = "$file$count";
    open my $write, '>', $new_name or die $!;
    while (my $line = <$read>) {
        print $write $line;
        if ($. % 25 == 0 and not eof $read) {
            $count++;
            close $write;
            $new_name = "$file$count";
            open $write, '>', $new_name or die $!;
        }
    }
}